Russia held municipal and regional elections throughout the country on Sunday that had been marked by a wave of pro-opposition protests in the run-up to the vote.

Senior Russian officials have asserted that foreign powers have been supporting the protesters.

A senior lawmaker threatened last week to expel German state broadcaster, Deutsche Welle, as it refused to attend a parliamentary hearing on an allegation that its coverage was interfering in Russian affairs.

A Deutsche Welle reporter was briefly detained while covering a Russian political opposition protest in Moscow in July.

Officials in the U.S. have previously implicated the Russian state in attempts to interfere in the 2016 U.S. presidential election in favour of Donald Trump, who had expressed personal admiration for Russian President Vladimir Putin.

The U.S. government has indicted several Russian nationals on such charges. Putin has denied Russian state involvement.

Relations between Russia and the West have plummeted to their frostiest point since the Cold War in recent years since Russia annexed neighbouring Ukraine’s Crimea region in 2014.

Russia’s leadership on Monday lent support to a federal investigation into the Russian election meddling claims against Google and Facebook.